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Abstract:

A control system is provided for shifting an automatic transmission of a
motor vehicle, which includes, but is not limited to a speed controller,
and an electronic control device. Through the electronic control device
the parameters vehicle speed, position of the speed controller and
acceleration of the speed controller can be captured. Through the
electronic control device and through comparison of the captured values
of the parameters with predetermined reference values a shifting time is
determined for shifting the automatic transmission.

Claims:

1. A control system for shifting an automatic transmission of a motor
vehicle, comprising: a speed controller; and an electronic control device
that is configured to: capture a vehicle speed, a position of the speed
controller, and an accelerator of the speed controller; compare the
vehicle speed, the position of the speed controller, and the accelerator
of the speed controller with predetermined reference values a shifting
time; and determine the shifting time for downshifting the automatic
transmission from the compare of the vehicle speed, the position of the
speed controller, and the accelerator of the speed controller with the
predetermined reference values.

2. The control system according to claim 1, wherein the electronic
control device is further configured to determine an acceleration of the
speed controller as a function of a change of the position of the speed
controller.

3. The control system according to claim 1, wherein the shifting is a
downshifting.

4. A method for controlling a shifting of an automatic transmission of a
motor vehicle, comprising: capturing a speed of the motor vehicle with
speed sensor; capturing a position of a speed controller; capturing an
acceleration of the speed controller; comparing the speed, the position,
and the acceleration with predetermined reference values in an electronic
control device; determining a shifting time for the automatic
transmission; and shifting corresponding to the shifting time.

5. The method according to claim 4, wherein the shifting is a
downshifting.

6. The method according to claim 4, wherein the speed sensor is an angle
sensor.

7. The method according to claim 4, wherein the capturing the
acceleration of the speed controller is captured via at least one
acceleration sensor.

8. The method according to claim 4, further comprising determining the
acceleration of the speed controller as a function of a change of the
position of the speed controller.

[0002] This technical field relates to a control system for shifting an
automatic transmission of a motor vehicle, in particular for downshifting
an automatic transmission.

BACKGROUND

[0003] An automatic transmission is not a normal manual transmission. The
control of the clutch and the change of the gear are not brought about by
the driver, but for example by actuators or hydraulics. During the gear
change, the torque transmission, exactly with conventional manual
transmissions, is interrupted, and the shifting time is determined by the
time of the gear change plus the time for the clutch actuation. A driver
can select a gear to be engaged without having to manually carry out the
clutch operation.

[0004] The changing of the gears with an automatic transmission in this
case can be carried out with the help of a shifting curve, which has been
generated as a function of a position of a speed controller and of a
vehicle speed. The term speed controller describes a controller, which
controls the power of the engine. The speed controller can be designed
for example in the form of a rotary knob, of a lever, a touch-sensitive
area or of an accelerator pedal. For example, upon a slow actuation of
the speed controller of the motor vehicle in order to for example to
allow the motor vehicle to roll out to a stop, the automatic transmission
can react unevenly, for example nervously or aggressively, which can
manifest itself for example as a jerking of the motor vehicle or as a
loud engine noise.

[0005] In view of the foregoing, at least one object is to make available
a control system for shifting, in particular for downshifting an
automatic transmission for motor vehicles, which makes possible increased
comfort during driving during the changing of the gears in an automatic
transmission. In addition, other objects, desirable features and
characteristics will become apparent from the subsequent summary and
detailed description, and the appended claims, taken in conjunction with
the accompanying drawings and this background.

SUMMARY

[0006] An embodiment relates to a control system for shifting, in
particular for downshifting an automatic transmission of a motor vehicle,
comprising a speed controller, an electronic control device. Through the
electronic control device the parameters of vehicle speed, position of
the speed controller and accelerator of the speed controller can be
captured. Through the electronic control device and through adjusting the
captured values of the parameters with predetermined reference values a
shifting time, in particular a shifting time for downshifting the
automatic transmission can be determined.

[0007] The electronic control device can be connected to the speed
controller and to the automatic transmission. The electronic control
device can capture at different parameters. The values of the parameters
can be captured directly through sensors connected to the electronic
control device, or captured indirectly. The values during the indirect
capture can be derived from further information. Here, the parameters can
comprise a vehicle speed, a position of the speed controller and/or an
acceleration of the speed controller. Here, the vehicle speed for example
can be driven with a speed sensor or be derived from information, for
example a rotational wheel speed. The position of the speed controller
can be captured for example with the help of an angle sensor. The angle
sensor for example can output a percentage value to the electronic
control device. A value of approximately 0% can correspond to a zero
position and a value of approximately 100% to a full load position of the
speed controller. The acceleration of the speed controller can be
captured for example with an acceleration sensor arranged on the speed
controller.

[0008] In the electronic control device, reference values for shifting
times can be stored for example in a storage element. The reference
values, in particular the reference values from value triples of the
vehicle speed, the position of the speed controller and the acceleration
of the speed controller can be assigned to certain gear changes, for
example from the sixth into the fifth gear or from the fourth into the
second gear. In the predetermined reference values for shifting the
automatic transmission, in particular for downshifting, it can be
determined by how many gears the automatic transmission will shift at the
assigned shifting time. For example, with a low or constant acceleration
of the speed controller, a shifting time, in particular a shifting time
for downshifting the automatic transmission can be determined, which
engages the gears one after the other while with a high acceleration of
the speed controller, for example a shifting time, in particular a
shifting time for downshifting the automatic transmission can be
determined, wherein one or a plurality of gears can be skipped. Here, the
acceleration is the change of the speed with which the speed controller
is actuated.

[0009] The captured values of the parameters can be continuously compared
with predetermined reference values in the electronic control device.
With the help of the reference values, shifting times of the automatic
transmission, in particular shifting times for downshifting can be
determined As soon as the captured values of the parameters coincide with
predetermined reference values, the shifting time of the automatic
transmission can be determined through the electronic control device,
wherein the automatic transmission can be shifted, in particular
downshifted in accordance with the gear changes assigned to the reference
values. Because of this, the control system can also skip gears during
the shifting of an automatic transmission, as a result of which an
uneven, for example a nervous or aggressive shifting behavior can be
avoided through a rapid serial change of the individual gears. Because of
this, the electronic control device can determine a shifting time, in
particular a shifting time for downshifting the automatic transmission
with a corresponding gear change, which can be adapted to the driving
state of the motor vehicle. Because of this, an uneven, for example a
nervous or aggressive shifting of the automatic transmission can be
prevented, as a result of which the driving comfort can be increased.

[0010] Preferentially, the electronic control device is configured in such
a manner that the electronic control device determines the acceleration
of the speed controller as a function of a change of the position of the
speed controller. Because of this, the electronic control device can
capture the acceleration with which the speed controller is actuated, for
example with an increasing, constant or decreasing acceleration. As a
function of the acceleration and/or position of the speed controller, the
electronic control device can indirectly calculate and/or derive the
acceleration and/or change of the position of the speed controller. In
conjunction with the parameters vehicle speed and position of the speed
controller and by comparing with a predetermined reference value, the
electronic control device can determine a shifting time with an assigned
gear change of the automatic transmission. Through the indirect capturing
of the acceleration, an acceleration sensor for example can be saved, as
a result of which cost savings can be made possible.

[0011] A further embodiment is a motor vehicle having at least one control
system for shifting, in particular for downshifting an automatic
transmission for motor vehicles. Through the control system, the
electronic control device of the control system can compare the captured
parameters with predetermined reference values and determine a shifting
time of the automatic transmission, and thus increase the driving
comfort.

[0012] Furthermore, a method is claimed for controlling a shifting, in
particular a downshifting of an automatic transmission of a motor
vehicle, comprising the steps: capturing a speed of the motor vehicle,
capturing a position of a speed controller, capturing an acceleration of
the speed controller, comparing the captured values with predetermined
reference values in the electronic control device for determining a
shifting time, in particular of a shifting time for downshifting the
automatic transmission, shifting, in particular downshifting the
automatic transmission corresponding to a gear changed assigned to the
reference value concerned.

[0013] Through the method it is possible that for example at a low or
constant acceleration of the speed controller a shifting time can be
determined, at which for example gears can be changed one after the
other, while for example upon a high acceleration of the speed
controller, a shifting time with an associated gear change can be
determined, wherein a plurality of gears can be skipped, wherein for
example at least one or a plurality of gears can be skipped.

[0014] The method the vehicle speed is preferably captured by way of at
least one speed sensor. Because of this, the electronic control device
can capture the speed of the motor vehicle and as a function of the
position of the speed controller and the acceleration of the speed
controller through comparison with predetermined reference values,
determine a shifting time, in particular a shifting time for downshifting
the automatic transmission, thus increasing the driving comfort.

[0015] With the method, the position of the speed controller can be
preferentially captured by way of at least one angle sensor. The angle
sensor can for example output a percentage value to the electronic
control device. A value of approximately 0% can correspond to a zero
position and a value of approximately 100% to a full load position of the
speed controller. Because of this, the electronic control device can
capture the position of the speed controller and as a function of the
vehicle speed and the acceleration of the speed controller through
comparison with a reference value determine a shifting time, in
particular a shifting time for downshifting the automatic transmission,
thus increasing the driving comfort.

[0016] It is preferred that with the method, the acceleration of the speed
controller is captured by way of at least one acceleration sensor. The
acceleration sensor can be arranged on the speed controller. Because of
this, the electronic control device can capture the acceleration of the
speed controller and as a function of the vehicle speed and the position
of the speed controller through comparison with a reference value,
determine a shifting time, in particular a shifting time for downshifting
the automatic transmission, thus increasing the driving comfort. With the
method, the electronic control device can preferably determine the
acceleration of the speed controller as a function of the change of the
position of the speed controller.

[0017] Because of this, the electronic control device can determine the
acceleration with which the speed controller is actuated, for example
with an increasing, constant or decreasing acceleration. As a function of
the acceleration and/or position of the speed controller, the electronic
control device can indirectly calculate and/or determine the acceleration
and/or change of the position of the speed controller. In conjunction
with the parameters vehicle speed and position of the speed controller
and through comparison with a predetermined reference value, the
electronic control device can determine a shifting time with an assigned
gear change of the automatic transmission. Through the indirect capturing
of the acceleration, the acceleration sensor can be saved. This can make
cost savings possible.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will hereinafter be described in conjunction
with the following drawing figures, wherein like numerals denote like
elements, and:

[0019] FIG. 1 is a simplified representation of an automatic transmission
with a control system;

[0020] FIG. 2 is a shifting curve as a function of the position of a speed
controller and of a vehicle speed; and

[0021] FIG. 3 is a plurality of shifting areas as a function of the
position and of the acceleration of the speed controller and of the
vehicle speed.

DETAILED DESCRIPTION

[0022] The following detailed description is merely exemplary in nature
and is not intended to limit application and uses. Furthermore, there is
no intention to be bound by any theory presented in the preceding
background or the following detailed description.

[0023] In FIG. 1, a simplified representation for a control system 10 for
shifting, in particular for downshifting an automatic transmission 12 for
a motor vehicle is shown. The control system 10 comprises an electronic
control device 14, a speed controller 16. The electronic control device
14 is connected to the speed controller 16 and to the automatic
transmission 12 for example in an electrically conductive manner for
transmitting measurement values of parameters.

[0024] The electronic control device 14 can capture different parameters.
The values of the parameters can be directly captured or indirectly
captured through sensors connected to the electronic control device. The
values with the indirect capture can be derived from additional
information. The parameters in this case can comprise a vehicle speed, a
position of the speed controller 16 and an acceleration of the speed
controller 16. Here, the vehicle speed for example can be determined with
a speed sensor or derived through the electronic control device 14 from
information, for example from a rotational wheel speed. The position of
the speed sensor can be captured for example with the help of an angle
sensor. The angle sensor for example can output a discrete angular amount
or a percentage value to the electronic control device 14. A value of
approximately 0% can correspond to a zero position and a value of
approximately 100% to a full load position of the speed controller 16.
The acceleration of the speed controller 16 can be captured for example
with an acceleration sensor arranged on the speed controller 16.

[0025] In the electronic control device 14, for example in a storage
element integrated in the electronic control device 14, reference values
for shifting times of the automatic transmission 12 with the assigned
gear changes can be stored. The reference values can be assigned to
certain gear changes, for example from the sixth into the fifth gear or
from the fourth into the second gear. In the predetermined reference
values for shifting the automatic transmission 12, in particular for
downshifting, it can be determined by how many gears the automatic
transmission 12 will shift. For example, at a low or constant
acceleration of the speed controller 16, a shifting time, in particular a
shifting time for downshifting the automatic transmission 12 can be
determined, which engages the gears one after the other, while upon a
high acceleration of the speed controller 16, a shifting time, in
particular a shifting time for downshifting the automatic transmission 12
can be determined, which will skip a plurality of gears, wherein at least
one or a plurality of gears can be skipped.

[0026] The captured values of the parameters can be continuously or
discontinuously compared with predetermined reference values in the
electronic control device for example as a function of a certain
acceleration value of the speed controller 16. As soon as the captured
values of the parameters coincide with one of the predetermined reference
values, a value triple with a value of the position of the speed
controller, a value of the acceleration of the speed controller as well
as a value for the vehicle speed, the shifting time of the automatic
transmission 12 can be determined through the electronic control device
14. The automatic transmission 12 can be shifted corresponding to a gear
change assigned to the reference value concerned. Because of this, the
control system can also skip gears during shifting, in particular during
downshifting an automatic transmission, as a result of which an uneven
for example a nervous or aggressive shifting behavior can be avoided.

[0027] In FIG. 2, a shifting curve 18, in particular a shifting curve 18
for downshifting an automatic transmission 12 for a motor vehicle (not
shown) is shown, wherein the shifting curve 18 is assigned to a certain
gear change, for example the gear change from a second into a first gear
during a downshifting, as a function of the vehicle speed and the
position of the speed controller 16. The individual points of the
shifting curve in this case constitute value pairs, by means of which the
shifting curve is described. The value pairs of the shifting curve 18 can
be stored as reference value in a storage element of the electronic
control device 14. The shifting curve 18 can be used in an electronic
control device 14 in order to actuate the automatic transmission 12 of
the motor vehicle. On the y-axis, which is designated `position of the
speed controller`, the position of the speed controller 16 in % is
stated, where at approximately 0% the speed controller 16 is in a rest
position and at approximately 100% the speed controller 16 is completely
actuated. The value approximately 0% designates the origin of the y-axis.
On the x-axis, which is designated `vehicle speed`; the speed of the
vehicle is indicated. The position of the speed controller 16 in this
case can be captured via an angle sensor and the vehicle speed can be
captured with the help of a speed sensor.

[0028] A gear change of the automatic transmission 12 with the shifting
curve exemplarily shown in FIG. 2 is explained in more detail in the
following. A gear change takes place when the shifting curve is
intersected by values of the x and y-axis. For example, both the position
of the speed controller 16 as well as the vehicle speed has a value of
the point A. With a constant position of the speed controller 16, the
motor vehicle travels with a constant speed. As soon as the vehicle speed
changes, for example when the vehicle travels uphill, and the driver does
not change the position of the speed controller 16, the vehicle speed
changes simultaneously and the value of the vehicle speed migrates along
the interrupted line in the direction of the y-axis. The electronic
control device 14 captures the position of the speed controller 16 and
the reduction of the vehicle speed. As soon as the value of the vehicle
speed intersects the shifting curve 18 without the position of the speed
controller 16 changing, a shifting operation for downshifting the
automatic transmission 12 is triggered by the electronic control device
14.

[0029] In a further example, the position of the speed controller 16
changes and the vehicle speed remains constant. For example, both the
vehicle speed as well as the position of the speed controller 16 has a
value of the point B. As soon as the driver changes the position of the
speed controller 16 without changing the vehicle speed, for example when
rolling downhill, the value of the position of the speed controller 16
migrates along the interrupted line towards the x-axis. As soon as the
shifting curve is intersected, the shifting curve is exceeded and a
shifting operation for downshifting the automatic transmission 12 is
triggered by the electronic control device 14.

[0030] However, when using such shifting curves for a gear change in an
automatic transmission 12, skipping gears is not possible. For example,
when downshifting from the eighth gear into the fifth gear, the automatic
transmission 12 has to individually downshift all gears from the eighth
gear to the fifth gear one after the other. This results in an uneven,
for example in a nervous or aggressive shifting behavior of the automatic
transmission, which can manifest itself through a jerking of the motor
vehicle or through a loud revving up of the engine.

[0031] FIG. 3 shows a three-dimensional shifting space for an automatic
transmission 12 for a motor vehicle defined by the parameters vehicle
speed, position of the speed controller 16 and acceleration of the speed
controller 16. The shifting space shown in FIG. 3 is used in an
electronic control device 14 in order to actuate the automatic
transmission 12 of the motor vehicle. The vehicle speed can be captured
with a speed sensor. The position of the speed controller 16 can be
captured with an angle sensor. The acceleration of the speed controller
16 can be captured by way of an acceleration sensor. However, it is also
possible that the electronic control device 14 derives the acceleration
of the speed controller 16 as a function of the change of the position of
the speed controller 16.

[0032] In the defined three-dimensional shifting space, the position of
the speed controller 16 in % is indicated on the y-axis, which is
designated `position of the speed controller`, where a value of
approximately 0% can correspond to a zero position and a value of
approximately 100% to a full load position of the speed controller 16. On
the x-axis, which is designated `vehicle speed`, the vehicle speed is
indicated. On the z-axis, which is designated `acceleration of the speed
controller`; the speed of the change of the position of the speed
controller 16 in % per second is stated.

[0033] The predetermined reference values for shifting times with the
respective assigned gear changes, in particular the shifting times for
downshifting the automatic transmission 12 can form a shifting area 20 in
the x, y and z-plane. Each gear change can be assigned a shifting area
20, wherein the shifting areas 20 partially coincide, meaning being at
least partially formed from the same value triple. This is the case for
example upon a gear change wherein a gear is skipped.

[0034] In the shifting areas, the shifting behavior, in particular the
shifting behavior for downshifting the automatic transmission 12 can be
stored. For example it can be possible that at a low or constant
acceleration of the speed controller 16, the captured values of the
parameters can intersect a shifting area 20 of the predetermined
reference values, in which a shifting time, in particular a shifting time
for downshifting the automatic transmission can be determined, in which
for example the gears can be shifted one after the other. Upon a high
acceleration of the speed controller 16, the captured values of the
parameters can intersect a shifting area 20 of the predetermined
reference values in which the gears can be skipped, wherein at least two
gears can be skipped as the gear before the shifting.

[0035] In FIG. 3, three different shifting areas 20 are exemplarily shown.
The shifting areas 20 each are formed from reference values of value
triples. Each reference value is assigned a certain gear change. The
shifting areas 20 are arranged in the shifting space defined from the
parameters position of the speed controller 16, acceleration of the speed
controller 16 and vehicle speed. As soon as the captured parameters, in
particular the captured value triples, coincide with one of the shifting
areas 20, a corresponding shifting time with an associated gear change
can be determined by the electronic control device 14.

[0036] A shifting, in particular a downshifting of the automatic
transmission 12 can take place for example as follows: the electronic
control device 14 can capture the vehicle speed, the position of the
speed controller 16 and the acceleration of the speed controller 16, for
example with the help of sensors. In the shifting space, the captured
parameters can for example define a first point (not shown) corresponding
to the parameter values. The electronic control device 14 continuously
monitors the vehicle speed, the position of the speed controller 16 and
the acceleration of the speed controller 16. As soon as for example the
vehicle speed changes through a change of the position of the speed
controller 16, the electronic control device 14 captures these changes
and simultaneously captures the acceleration of the speed controller 16
in order to capture the speed of the change of the position of the speed
controller 16. Because of this, the value triple of the parameters
changes its position in the shifting space. The parameter values migrate
from the first point through the shifting space as far as to a second
point (not shown). The second point in the shifting space corresponds to
the parameter values of the changed vehicle speed, the changed position
of the speed controller 16 and the acceleration of the speed controller
16. The electronic control device 14 continuously compares the values of
the vehicle speed, position of the speed controller 16 and the
acceleration of the speed controller 16 with the predetermined reference
values during the migration from the first point through the shifting
space up to the reaching of the second point. As soon as the parameter
values on the route to the second point intersect a shifting area
corresponding to the predetermined reference values, a shifting time, in
particular a shifting time for downshifting the automatic transmission 12
is reached. The automatic transmission 12 can be shifted with the
assigned gear change. The shifting time determined by the electronic
control device 14 can for example comprise a delay time. The automatic
transmission 12 upon coinciding of the measured parameters with the
reference values is only shifted with an assigned gear change upon a
determined time delay.

[0037] For example, with a low or constant acceleration of the speed
controller 16, a shifting time, in particular a shifting time for
downshifting the automatic transmission 12 can be determined, which
engages the gear one after the other, while with a high acceleration of
the speed controller 16, for example a shifting time, in particular a
shifting time for downshifting of the automatic transmission 12 can be
determined, which can skip a plurality of gears.

[0038] While at least one exemplary embodiment has been presented in the
foregoing summary and detailed description, it should be appreciated that
a vast number of variations exist. It should also be appreciated that the
exemplary embodiment or exemplary embodiments are only examples, and are
not intended to limit the scope, applicability, or configuration in any
way. Rather, the foregoing summary and detailed description will provide
those skilled in the art with a convenient road map for implementing an
exemplary embodiment, it being understood that various changes may be
made in the function and arrangement of elements described in an
exemplary embodiment without departing from the scope as set forth in the
appended claims and their legal equivalents.

Patent applications by Gernot Becker, Mainz DE

Patent applications by Martin Gentile, Ruesselsheim-Koenigstaedten DE

Patent applications by GM GLOBAL TECHNOLOGY OPERATIONS LLC

Patent applications in class Feedback control (e.g., closed loop)

Patent applications in all subclasses Feedback control (e.g., closed loop)